It is only selflessness persons like you can do this. Anyone who have the heart to grow others both in the forum and in real life have the life style of charity.
You are interpreting the merit distribution in the wrong manner as it's not like charity because it means helping the people but in actual these threads and merits are given to those who deserves them based on post of their quality only so you see it's different way of handing out merits on the forum.He is merit source and distribute merits from what he get as source and also smerits he has earned from his effective contributions on forum so he would then in return share it with some good low ranking members.
I am trying to grow good posters, teaching them how to write good posts and rewarding them for their efforts.
This way they will learn how to rank up on forum with your other threads as well getting merits from you on the good post and if you give all of them merits then they will never understand how to earn them through effective posting so your approach is very well that you are helping them to grow as well as learn which would help them to gain more merits in the long run as knowledge is key to success and we learn with time and dedication.
50 merit for a good poster are normal and they may not be as happy as a poster trying to improve the quality of post even if it only gets 1 merit.
On my personal approach I still feel happy whenever I get one merit also because it boost my motivation that my contributions have been recognised and was helpful for someone on the forum.The merits boost up your morale to write more good and useful stuff on the forum to earn more merits but if we compare it with low rank members then yes they are more happy to get merits seeing themselves rank on the forum I would say rather based on 50 or 1 merit.But this system has helped to reduce spam to some extent as they cannot rise on the forum if they don't have zeal to learn and write useful post on the forum.